Bachelor’s degrees from private colleges have the highest returns on investment 40 years after enrollment, a new report released Thursday by the Georgetown University Center on Education and the Workforce in Washington, D.C. “A First Try at ROI: Ranking 4,500 Colleges” asks the $1.5 trillion question: Is college worth it?

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Of the 10 colleges with the best long-term net economic gain after 40 years, all are four-year institutions, and eight are private nonprofit institutions, the report said. The colleges that predominantly offer certificates or associate’s degrees have the highest return on investment 10 years after enrollment.

Of the 10 colleges with the best long-term net economic gain after 40 years, all are four-year institutions, and eight are private nonprofit institutions.

Two public four-year institutions, Maine Maritime Academy and the U.S. Merchant Marine Academy, rank in the top 10 colleges with the best long-term returns, while two four-year private colleges, St. Louis College of Pharmacy and Albany College of Pharmacy and Health Sciences, made the top 10 for short-term and long-term returns.

The report ranks 4,526 colleges and universities by return on investment. Institutions with the highest returns after 10 years yield $1 million, and sometimes $2 million, after 40 years, exceeding the median 40-year returns of private institutions.

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The top 10 colleges with the highest net return after four decades

(See the full table here.)

The survey names these colleges as giving the biggest return on investment after four decades: Albany College of Pharmacy and Health Sciences, St. Louis College of Pharmacy, Massachusetts College of Pharmacy and Health Sciences, Massachusetts Institute of Technology, Stanford University, Maine Maritime Academy, Harvard University, United States Merchant Marine Academy, Babson College and Georgetown University.

Overall, returns on investment from bachelor’s degrees eventually overtake returns from most two-year credentials, it added. Case in point: Babson College, a private institution in Wellesley, Mass., ranks 304th in net present value at the 10-year mark, but it rises to seventh after 40 years.

“Everyone is asking, ‘Is college worth it?,’” said Anthony Carnevale, the lead author and director of Georgetown’s Center on Education and the Workforce. “This kind of information on the costs and benefits of higher education holds institutions more accountable.”

Institutions with the lowest long-term economic value range from theological institutions and beauty schools to colleges specializing in the arts.

“Even though students, on average, take out more than twice as much in loans to attend private colleges, a degree from a private nonprofit college is worth $8,000 more annually 10 years after enrollment,” the report said. The institutions with the lowest long-term economic value include theological institutions, beauty schools and colleges specializing in the arts.

Colleges that award associate’s degrees and certificates show the highest returns on investment 10 years after enrollment. Twenty-six of the 30 institutions with the best short-term net economic gains primarily grant certificates or associate’s degrees.

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After four decades, however, the average graduate of a private college has a net economic gain of $838,000, even after paying off higher amounts of debt — 9.5% more than the $765,000 net financial gain for a graduate of a public college.

The report uses data from the expanded College Scorecard, an online tool created by the U.S. government in 2015, from 4,500 colleges, including traditional two-year and four-year public and private colleges, as well as for-profit colleges and training academies.

Here are other key points from the report:

• Ten years after enrollment, the median net present value for all colleges is $107,000; that rises to $723,000 after 40 years.

• Colleges that primarily award associate’s degrees have the highest short-term return, a median of $141,000 10 years after enrollment.

• In the long term, the net economic gains for attending a private for-profit college are $551,000, versus $838,000 for a private nonprofit college and $765,000 for a public college.